Subsequent to spinal cord injury, a person's ability to maintain his or her level of pre-injury physical fitness is severely limited. The opportunities to participate in health promoting physical activities are less than a person enjoyed before injury, and dependence on wheeled mobility does not provide a source of motivation to exercise and keep fit. Several studies have shown that the average physical activity level of people with spinal cord injuries is well below that of the rest of the population. The lack of physical activity in people with spinal cord injury has led to an increase in the prevalence of cardiovascular disease. The specific aim of this project is to provide an avenue for reducing the incidence of cardiovascular disease among people with spinal cord injury by providing a product that both improves cardiovascular fitness and is fun to use . This goal will be accomplished by the development of a system that allows the wheelchair user to control commercially available video games, that uses a computer mouse or joystick as input, through forward and backward motion of the chair's wheels. The wheelchair will be mounted on a roller system that prevents the wheelchair from moving during play. PROPOSED COMMERCIAL APPLICATION This system will be commercially attractive to people with spinal cord injuries who desire an alternative to arm crank exercise. GameWheels combines the enjoyment of playing video games with the health benefits of exercise. There are approximately 200,000 spinal cord injured people in the United States.